Not a particularly wet July, so far. The shark oil barometer has been crystal clear for quite sometime. It looks like today could bring some rain, but we will taper back to dry conditions, again.

Dewpoints across parts the region have fallen and remained low over the last week or so. Check out the dewpoints for Phoenix, Tucson, El Paso, Yuma and Flagstaff. Flagstaff is still near average, where the others have dropped significantly. For the month, with the rains before the 4th of July, we are still right about average for precipitation. That may not apply everywhere in the area due to the large variations possible in the monsoon season.

Looks like Flagstaff will be on the moisture edge for the next few days. There is very dry air to the west, very wet air to the east. Some days it may cause storms in Flag. Most storms will be to the east and southeast. It does appear the thermal low is starting to build over Baja and Southwestern Arizona.

As we await the start of the monsoon, the water temperatures around us seem to be important. The Pacific is apparently undergoing a signficant shift to an El Nino. Here is the animation of the global sea surface temperatures and anomaly. This could supply plenty of moisture if the monsoon gets started and draws from here. The Gulf of Mexico and Caribbean are near normal temperatures. Not as strong a moisture source. Also, the cooler water temps in the Gulf and Caribbean, and the El Nino should hinder hurricane season in the east.

Dewpoints have remained fairly high all month. We broached 50F for the dewpoint on Saturday. The average dewpoint (from Tucson NWS Tracking site) for the day was in the low 40’s. The moisture is trying to stream up from the Gulf of Mexico and is saturating Northern Mexico. It hasn’t quite made it to Arizona in full force, yet. One of the components of the monsoon is the formation of a thermal low pressure system. We are probably missing some heat to cause the lifting of the are to form the low pressure system.

Does this June seem cooler than last? Seems cloudier to me. Here is a comparison of the month so far:

Comparison of June 2008 to June 2009 Temperatures

The average temperature is the average for the given day, not the climatological normal. The low and average tempertures seem a little lower this year, compared to last year. But, the big difference is in the high temperatures. Seems like there has been more cloud cover with the cooler highs.

It looks like we will be heading for “normal” temperatures later this week and through the weekend.

Well, after May being mostly much warmer than normal, June is following the same trend as the end of May. This week’s normal high temperature is 77-78F, but we will be lucky to see temperatures above the mid-60’s. Forecasts and models for Tuesday are calling for precipitation, most likely scattered thunderstorms. Here is a graph of June weather to date from Wunderground:

Well, most of the forecasts are showing slight chances for isolated thunderstorms for the next few days. Go figure. It doesn’t match the computer models that I typically watch. I think the dewpoint is higher than we might normally expect to see in June. If more moisture and a low pressure system come through, we could see some rain. We should see wind.

Yesterday was an average day, temperature wise. It wil probably be cooler than that thhrough the weekend.

There are three(3) things below that bear reading. First is the NWS May summary for Flagstaff. It was quite warm…until the end. In the end we had record breaking rain and cold. Quite an interesting month… a quandry!

Below are temperature graphs for the month. They are self-explanatory.

It appears the trend will continue into June. Maybe not as wet, but probably more clouds than usual. Phantom Ranch had a record low temperature, yesterday.

…A MAY THAT STARTED AS ONE OF THE WARMEST MAYS ON RECORD ALSO
TURNED INTO ONE OF THE WETTEST…

THE FIRST 15 DAYS OF MAY SET A PACE FOR THE MONTH TO BE ONE OF THE
WARMEST ON RECORD WITH AN AVERAGE TEMPERATURE OF 56.8 DEGREES. A
LARGE PLUME OF MOISTURE THEN MOVED OVER THE AREA AND THE RECORD
SETTING PACE WAS SLOWED DUE TO THE PASSAGE OF SEVERAL WEAK LOW
PRESSURE SYSTEMS AND INCREASED CLOUD COVER. STARTING ON THE
18TH…THE FLAGSTAFF AIRPORT RECORDED PRECIPITATION ON 12 OF THE 15
REMAINING DAYS OF THE MONTH. AT LEAST A TRACE OF RAIN FELL AT THE
FLAGSTAFF AIRPORT FROM THE 20TH THROUGH 30TH. THIS 11 DAY RUN RANKS
2ND IN MOST CONSECUTIVE DAYS OF PRECIPITATION IN THE MONTH OF
MAY…AND 40TH FOR MOST CONSECUTIVE DAYS OF PRECIPITATION OVERALL.
THE RESULT WAS AN UNUSUALLY WET MAY…WITH 2.08 INCHES OF
PRECIPITATION BEING RECORDED. MAY 2009 ENDED AS THE 5TH WETTEST ON
RECORD…1.28 INCHES ABOVE THE NORMAL 0.80 INCHES OF PRECIPITATION
FLAGSTAFF NORMALLY RECEIVES IN MAY.

THE ABNORMAL PRECIPITATION STILL WAS NOT THE ONLY STORY OF
MONTH…ABNORMALLY HIGH TEMPERATURES ALSO WORKED THEIR WAY INTO THE
MIX. MAY 2009 WAS THE FIRST MAY EVER…TO NOT RECORD A LOW
TEMPERATURE OF 32 DEGREES OR BELOW. THE MONTH ENDED AS THE 2ND
WARMEST MAY ON RECORD WITH A MONTHLY AVERAGE TEMPERATURE OF 56.0
DEGREES. BREAKING THAT DOWN INTO THE HIGHS AND LOWS…THE AVERAGE
MINIMUM TEMPERATURE WAS 39.6 DEGREES…THE WARMEST AVERAGE MAY
MINIMUM TEMPERATURE EVER RECORDED. THE AVERAGE MAY MAXIMUM
TEMPERATURE CAME IN AS THE 8TH WARMEST MAY MAXIMUM WITH A VALUE OF
72.3 DEGREES.

There are a number of parts to looking at this summer. First we have a new tool available from NOAA (National Oceanic and Atmospheric Administration). This tool provides a local 3-month outlook by individual NWS weather station. This particular tool, which I have linked to from my main website, is showing an better chance at the summer being warm. This isn’t an unusual forecast for NOAA. They tend to be on the “everything is getting warmer” band wagon. However, their Climate Prediction Center is showing a chance for a wetter than average summer:

Summer 2009 - Precip Forecast

However, keep in mind my post from April 28, 2009 and the associated Intellicast article on the summer outlook. The Intellicast article takes into account several factors in analog years to predict the summer. Their prediction is towards a cooler summer. Unfortunately they level out a prediction for precipitation.

Usually, I like to look at the sea surface temperature anomaly in the waters that affect our precipitation. These would be the waters off the Baja Coast and the Gulf of Mexico. The Gulf of Mexico is fairly mild this year, so far. There is a body of warmer than normal water off the Baja, but there also appears to be a boundary of cooler water between us and there. In all, a wash for warm water driving more moisture to us.

So, in my mind, I think if we have cooler this summer, it could be wetter. If it is hotter, we could be drier.

It has been a wet month and the San Fancisco Peaks are white once again (Downtown Webcam can get you a picture). I recorded 0.66 inches of precipitation for a monthly total of 1.99 inches. This includes the snow-like hail that fell. The National Weather Service at the airport reported only 0.36 inches leaving them just short of the 0.46 inch record. This brought them to 2.08 inches for the month which is 1.29 inches, or more than double the normal for the month. The record for May is 4.14 inches. We’ll see what today brings, but we probably won’t be seeing a record month.

The last week’s precip looks like this from radar estimation(from Intellicast):

Radar estimation of precipitation, 5-24-09 to 5-31-09

It should dry out from here forward. There is a chance again today, but not as significant as yesterday. It continues to decline through this week. We should be warming slightly as well. It should be a great week for getting the scooter back out on the road. There is a chance for more rain around the middle of June.